A new bypass on the Fylde peninsula will eliminate bottlenecks on the road to the port of Fleetwood.
Perched at the northernmost point of the Fylde peninsula in north west England, the port town of Fleetwood occupies a prominent position overlooking Morecambe Bay. In recent years the area’s economy has been hit by the decline of the fishing industry and reduced commercial activity in the deep water port.
Efforts to attract new businesses and protect existing jobs have up until now been hampered by the poor reliability of the highway network.
The only trunk road linking Fleetwood to the wider UK system is the A585 which carries traffic through a series of small villages such as Little Singleton on single carriageway roads. Highway safety is compromised by the many residential properties with drives that exit straight onto the road.
Bottleneck
As well as being a major bottleneck for drivers going to and from Fleetwood, with regular congestion at peak hours, this part of the A585 is a hazard for pedestrians and cyclists, for whom no alternative routes exist.
But National Highways and its design-build contractor Kier Highways are midway through a £150M project to improve the reliability and safety of a section of the A585 between Windy Harbour Junction and Skippool.
Consultation on alignment options began in 2016 and Kier Highways – with its consultants RPS Group and Tony Gee & Partners – was appointed in March 2020. It started construction work on site in January last year after a period of detailed design and an extensive archaeological dig.
The scheme extends over 4.8km of highway, and encompasses junction improvements, dualling of some parts of the existing road, three new bridges, and a new bypass that will remove through traffic from Little Singleton’s residential roads.
At the north west end of the project, the five-way Skippool roundabout is being replaced by a signal-controlled crossroads so that peak-time traffic flows can be more effectively moderated.
A number of key milestones are coming up at this end of the route, explains Kier project manager Jonathan Hornsby. They include finishing the diversion of a major utilities pipeline that runs through the junction and redirecting traffic onto one half of a new bridge being built over a tributary of the River Wyre. Repairs to a 1.5m diameter culvert directly below the roundabout are also nearing completion.
The culvert which feeds into Skippool Creek had the potential to create a major headache for the project until the project team identified a much less disruptive solution than the conventional approach. Normally the repair would have required several traffic diversions so that the culvert could be removed and replaced in phases. This would have been annoying for drivers, complicated to plan, and would have had the potential to derail the programme if anything went wrong.
Instead, the culvert will be retrofitted with a glass fibre reinforced plastic lining that will extend its life and which can be put in place without interrupting traffic. The lining resin is cured using ultraviolet light.
“Although the capacity of the culvert will be slightly reduced, the surface of the new liner will be smoother than that of the existing concrete, and will improve the hydraulic profile,” Hornsby explains.
As well as eliminating the culvert from the critical path, this solution delivers additional environmental benefits by extending its life. This work is scheduled to take place later in the year when there is less risk of high water in the inlet and when the weather is more suitable.
Currently under construction just a short distance away is a 40m span integral bridge which will carry the highway over a small waterway which also runs into the Skippool Creek. The existing structure is little more than a double culvert with a parapet, so the new bridge will increase capacity and reduce the risk of flooding caused by blockages.
Poor ground conditions
After this point the alignment turns south across the floodplain, where it will run on a 5m high embankment over what Hornsby refers to as “fairly poor ground conditions”.
This alluvial material required a 1m deep drainage layer and a series of prefabricated vertical drains installed by Cofra to a depth of 12m to accelerate the consolidation of the embankment.
An extensive archaeological dig across this part of the site unearthed a significant range of finds, including Stone Age tools and a perfectly preserved 6,000 year old elm tree leaf which is currently on display in the Stonehenge exhibition at the British Museum.
“We had about 80 archaeologists on site,” recalls Hornsby. “The stone tools and pottery that they found together were evidence of a time when people were starting to move from being hunter-gatherers to being farmers.”
Across the flood plain the vertical alignment of the new route dips down to pass below a new bridge which is being built to carry Lancashire County Council’s Lodge Lane over the trunk road.
The cutting is being created top-down, with 200m long walls constructed along the sides using 1.4m diameter secant piles. A temporary bridge will be installed on the piles alongside Lodge Lane and traffic will be diverted onto it while the permanent 24m span bridge is built.
The eastern section of the work involves widening around 800m of existing highway leading up to Windy Harbour Junction.
According to National Highways project manager Tristram Bardrick, the scheme includes a number of environmental improvements to mitigate its impact on the pink-footed geese that overwinter in the area, and on wading birds such as lapwing and curlew.
New habitats have been created away from the construction site, by planting and managing specific crops to create the right foraging conditions for the birds across a 12.5ha area.
Hedgerows are also cut low to improve sightlines.
Five new scrapes, or shallow ponds, have also been created for the waders. Details of a new woodland scheme close to the route are currently being finalised. This is intended to reduce flood risk, create carbon storage capacity to help mitigate rising atmospheric levels of CO2, and to create an area for leisure pursuits.
Hornsby confirms that the site team is currently focused on bringing the target completion date of August 2023 forward by several months, potentially having the new road open to traffic in May next year.
Original Source: https://www.newcivilengineer.com/the-future-of/future-of-roads-new-bypass-eliminates-fylde-bottleneck-31-03-2022/